Description

The JavaScript String method slice() extracts and returns a section of a string based on the given index values.

  • It generates and returns a new string, and it doesn't modify the original string.
  • The starting index is inclusive and the ending index is exclusive.

Syntax

The method slice() has the below syntax, where str is a string.

str.slice(beginIndex, endIndex)

Parameters

The method slice() allows the below parameters.

beginIndex

  • It is the starting index for selection.
  • This index is inclusive, which means the extraction includes the character in this index.

endIndex (optional)

  • It is the ending index for selection.
  • This index is exclusive, which means the extraction doesn't include the character in this index.
  • If it is not provided, then the end of the string is considered.

Result

Returns a new string containing the extracted section of a string, based on given index values.

It doesn't modify the original string.

Example 1: Using the Method

The below example shows the basic usage of the method.

var str = "Learning JavaScript is fun";

// Using both start and end indices
document.write(str.slice(9, 19));     // Prints: JavaScript

// Using only start index
document.write(str.slice(9));     // Prints: JavaScript is fun

Output:

JavaScript
JavaScript is fun

Example 2: Method with Negative Indices

If we need to extract a portion of a string from the end, then we can use negative indices.

The negative indices are counted from backward, where -1 represents the last element, -2 represents the second element, and so on.

var str = "Learning JavaScript is fun";

// Using both start and end indices
document.write(str.slice(-17, -7));    // Prints: JavaScript

// Using only start index
document.write(str.slice(-17));        // Prints: JavaScript is fun

Output:

JavaScript
JavaScript is fun

Example 3: Method without Indices

If the indices are not provided, the method returns the complete string.

var str = "Learning JavaScript is fun";

// Method without indices
document.write(str.slice());    // Prints: Learning JavaScript is fun

Output:

Learning JavaScript is fun

Overall

The JavaScript String method slice() extracts and returns a section of a string based on the given index values.

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